Really, in my opinion, you don't need to work out any kind of special system if you have the right people with you who know how to roleplay, and are reasonable enough. Though others already mentioned this on here. Usually only beginner roleplayers think like this, when they need to learn that they themselves are not invincible, so why should their characters be? Especially if they are an ordinary african lion or gray wolf. Though even so, if your character has any kind of special power, they should be hit a couple times out of fairness. You also need to think about what kind of personality your character has. Do they want to be hit? Do they want to die? I suppose that sort of falls into the idea of plot though.
Roleplayers who are more experienced think of it as writing a story, in my mind, anyway.. And not all characters are perfect. While beginner roleplayers take it a tad too seriously and do whatever it takes for their characters to win.
I probably just said what everyone already thinks, but I just felt like spilling my idea on the matter if no one else said the exact same thing.
